Laminar battery system

ABSTRACT

A battery system comprises a plurality of substantially planar layers extending over transverse areas. The plurality of layers comprises at least one cathode layer, at least one anode layer, and at least one separator layer therebetween.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C. §119(e) of U.S.Provisional Patent Application No. 61/730,402, filed Nov. 27, 2012,entitled “Laminar Battery System,” the entirety of which is incorporatedby reference as if fully recited herein.

TECHNICAL FIELD

The subject matter of this disclosure relates generally to electronicdevices, and specifically to battery systems for portable electronicsand mobile devices. In particular, the disclosure relates to batterysystems with particular energy density, form factor and overall size andweight requirements.

BACKGROUND

Batteries come in a range of different architectures and forms,including traditional rod-and-tube (dry cell) and flat plate (floodedcell) designs, as well as “jelly roll” configurations in which the anodeand cathode layers are laid down on opposite sides of a flat sheet orflexible substrate and rolled up for insertion into the battery case orpouch. In flat battery designs, the rolled anode and cathode structureis folded into a low-profile casing or pouch, which is sealed along oneor more sides.

Battery configurations for portable electronics and mobile devicesrequire a range of design tradeoffs, including size, weight, powerconsumption, manufacturability, durability and thermal loading. Ingeneral, the amount of energy or storage capacity per battery weight (orvolume) can also be an important factor, because a greaterenergy/battery weight or volume ratio makes for a better, longer lastingbattery

SUMMARY

Exemplary embodiments of the present disclosure include battery systems,and methods of making the battery systems. The battery systems maycomprise a plurality of substantially planar layers extending over atransverse area. The plurality of layers may include at least onecathode layer, at least one anode layer, and at least one separatorlayer therebetween.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a battery with increased energy densityand improved form factor.

FIG. 2 is a cross-sectional view of the battery.

FIG. 3 is an enlarged cross-sectional view of the battery, showing thelaminar structure of the battery core.

FIG. 4 is an alternate cross sectional view of the battery, showing thelaminar core structure in an alternating anode/cathode layerconfiguration.

FIG. 5 is a schematic diagram of a method for producing a laminarbattery core.

FIG. 6A is a cross-sectional illustration of a cathode layer for alaminar battery core.

FIG. 6B is a cross-sectional illustration of anode and cathode layersfor the laminar battery core.

FIG. 6C is a cross-sectional illustration of a core stack element forthe laminar battery core, with anode and cathode layers, anode collectorand flexible sealant.

FIG. 7A is a schematic illustration of the laminar battery core stack,illustrating different external connector configurations.

FIG. 7B is a schematic illustration of the laminar battery core stack,in a single-side stack configuration.

FIG. 7C is a schematic illustration of the single-side stackconfiguration, illustrating representative layer thicknesses.

FIG. 8 is a schematic illustration of the laminar battery core stack, ina double-sided configuration.

FIG. 9 is a schematic illustration of the laminar battery core stack, ina single-sided, double stack configuration.

FIG. 10 is a schematic illustration of the laminar battery core stack,in a multi-stack configuration.

DETAILED DESCRIPTION

FIG. 1A is a perspective view of battery assembly 10 with pouch or outercasing 12 and protective wrap or film 14, which may be used forshipping, or for protection from damage and corrosion. An encapsulant orother sealing material 16 may be utilized to seal battery casing 12 toprevent leakage of electrolytes and other materials from the inside ofbattery assembly 10, to inhibit moisture intrusion, and to reduceoxidation and corrosion of the anode and cathode surfaces.

In the particular configuration of FIG. 1, battery assembly 10 has asubstantially oblong or rectangular geometry or form factor, with widthW defined between opposite sides 18A and 18B, length L defined betweenopposite sides or ends 19A and 19B, and thickness T defined betweenopposite major surfaces 20A and 20B. The battery core is provided withincasing 12, and is configured for increased energy density, as describedbelow, within an improved form factor (or volume envelope), as definedby length L, width W and thickness T.

Length L and width W are typically measured along first and second majorsurfaces 20A and 20B of battery system 10, in the direction of(horizontal) axes x and y, excluding the thickness of protective wrapperor film 14. Similarly, height or thickness T is measured between majorsurfaces 20A and 20B, along (vertical) axis z, also excluding protectivewrapper 14.

In low-profile or flat configurations of battery assembly 10, thicknessT is generally less than length L or width W, so that major surfaces 20Aand 20B have substantially greater surface area than side and endsurfaces 18A, 18B, 19A and 19B. The orientation of coordinate axes x, y,and z is arbitrary, however, and the various dimensions of length L,width W, and thickness T may also be interchanged, depending onconfiguration.

Connector 22 provides electrical power and signal connections to batteryassembly 10, for example in a “pig tail” configuration with a connectorboard 23 coupled to battery assembly 10 via flex circuit 24, as shown inFIG. 1. Depending on application, connector 22 and flex circuit 24 maybe configured to accommodate a range of different connection geometries,for example along a side surface (e.g., side 18A or 18B) or an endsurface (e.g., end 19A or 19B) of battery casing 12, or at a cornerinterface (e.g., between side 18A and end 19A, as shown in FIG. 1).

Where battery dimensions including length L, width W, and thickness Tare constrained, increased energy density provides battery system 10with greater storage capacity within a given form factor, and longerservice life between charges. Increased energy density also allows forreducing the form factor at a given storage capacity, or a combinationof increased capacity and reduced battery dimensions, for overallimprovements in both battery life and form factor or size envelope.

FIG. 2 is a cross-sectional view of battery system (battery assembly orbattery) 10, taken along line 2-2 of FIG. 1. Battery case or pouch 12 isformed about inner battery element or core 28, which stores electricalenergy and provides voltage and current. Protective wrapper 14 may beformed of an thin polymer sheet, for example a polyethyleneterephthalate (PET) film, and provided to cover battery 10 duringshipping, for example utilizing insignia 14A for identification.

Battery casing 12 is typically formed of a laminated material, forexample an aluminum alloy core layer 12A with plastic or polymerinsulating layers 12B and 12C on the inner and outer surfaces.Typically, core layer 12A provides strength, durability and structuralintegrity, and while coating layers 12B and 12C provide electricalinsulation and chemical protection from caustic materials in batterycore 28, for example acid or alkali electrolytes or other activecomponents 28A. Alternatively, battery casing 12 may be formed of apolymer material, or using an encapsulant, conformal coating or sealantmaterial, for example as described with respect to sealing material 16.

Battery core 28 comprises a laminated structure, as shown in FIG. 2,with active materials 28A interspersed between inactive or passivematerials 28B. Active materials 28A include at least one or both of thecathode and anode layers, as described in more detail below. Inactivematerials 28B may include spacers, insulators or substrate materials,which separate the anode and cathode pads. Although three layers ofactive material 28A and two spacer layers 28B are shown, the number ofindividual layers varies, depending on the design of battery system 10and battery core 28, and additional or fewer layers are contemplated.

To improve the energy density and storage capacity of battery system 10,battery core 28 is provided with an improved laminated structure toincrease the relative volume of active materials 28A, as compared toinactive or passive (spacer) materials 28B. This also contrasts withrolled battery core designs, for example, where there are substantialside roll regions, with relatively low energy density. In the laminarstructure of battery core 28, on the other hand, active and passivelayers 28A and 28B are substantially planer across most or substantiallyof the full length and width (that is, transverse area) of battery core38, including end regions 30.

This laminar and substantially planar configuration for battery core 28substantially reduces spacing issues presented by building anode andcathode layers into a rolled core configuration, where (1) there is asubstantial amount of side roll that does not significantly contributeto battery capacity, and (2) there is a substantial spacing between theanode and cathode pads, which is required to prevent shorting in thehigh curvature side roll regions.

In contrast, active and passive layers 28A and 28B of battery core 28are substantially flat and planar across substantially the full lengthand width of battery assembly 10, as shown in FIG. 2, increasingcapacity by providing relatively more substantially planar area inbattery core 28, with relatively higher energy density and moreefficient energy storage. The substantially planar, laminarconfiguration of battery core 28 also reduces the non-planar side rollareas, as provided in a rolled core design, and which have relativelylower energy density and relatively less efficient energy storage. Theseeffects may be particularly relevant in flat-profile form factordesigns, as shown in FIGS. 1 and 2, where the side roll curvature ishigh, and only the relatively straight or planar portions of the batterycore significantly contribute to overall battery capacity and storagecapability.

Laminar, substantially planar battery core 28 also reduces the requiredspacing between the anode and cathode pads, because tolerance is easierto maintain across the flat-plane structure of active and passivematerial layers 28A and 28B, as compared to a rolled design, withreduced risk of the anode and cathode pads accidentally touching, andshorting out the battery. This also increases energy storage density, byproviding more active material 28A per unit volume of battery core 28,including relatively more cathode thickness or volume, as compared topassive material 28B.

FIG. 3 is an enlarged cross-sectional view of battery 10, showing theinternal laminar structure of battery core 28. As shown in FIG. 3,battery core 28 is formed with alternating layers of active material 28Aand passive materials 28B, for example insulators or substrates,positioned between upper and lower portions of battery casing 12, andencapsulated with an epoxy, polymer, or other encapsulating material 16.

Battery casing 12 provides a mechanical, electrical and chemical barrierto isolate battery core 28 of battery 10, as described above. Dependingon embodiment, battery casing 12 may extend along the sides of batterycore 28, as shown in FIGS. 1 and 2, or encapsulating material 16 may beexposed on the sides, as shown in FIG. 3. Encapsulating material 16 mayalso be provided in a range of different thicknesses, and applied eitheracross the full height or thickness of battery core 28, as shown on theleft side of FIG. 3, or distributed across individual layers 28A ofactive material, as shown in the right side of FIG. 3.

Active material 28A is formed of anode layers 32 and cathode layers 34,spaced apart by separator layers 36. Pads or conductor (collector)layers 37 and 39 are provided adjacent anode and cathodes 32 and 34,respectively. As shown in FIG. 3, the top and bottom anode/cathodestructures have an inverted or double-sided stack orientation, withadjacent cathode layers 34 separated by a single anode pad layer 39.

Thus, three layers of active material 28A are shown, including two anodelayers 32 and two cathode layers 34, separated by two spacer layers 36.Alternatively, additional or fewer anode, cathode, spacer, and collectorlayers 32, 34, 36, 37, and 39 may be included. In additionalconfigurations, collector layers 37 and 39 may be defined as eitheractive or passive material, in which case the example of FIG. 3 could beconsidered to have three or four active layers 28A, and two or threepassive or inactive layers 28B.

Anode layers 32 and cathode layers 34 are formed of suitable anode andcathode materials including, but not limited to, lithium cobalt oxide,lithium iron phosphate, lithium manganese oxide, lithium, lithium metalphosphates, carbon, and graphite, for example graphite infused withlithium ions. In one particular configuration, for example, anode layer32 is formed of lithium, and cathode layer 34 is formed of lithiumcobalt oxide. Alternatively, anode layer 32 may be formed of lithiumcobalt oxide, or another lithium or metal oxide material, and cathodelayer 34 may be formed of graphite. Depending on the charging ordischarging state of battery 10, moreover, charge flow in anode andcathode layers 32 and 34 may reverse, as described below, without lossof generality.

Separator layer 36 is formed of a suitable insulating separator materialthat is permeable to ion transport, for example a porous polymer ormicroporous polyethylene lithium ion transport material, or a paper orfibrous composite material.

Anode and cathode pads or collector layers 37 and 39 may be formed ofsuitable conducting metals such copper or aluminum. Alternatively, thelithium anode may be utilized, at least charge transport inside battercore 28.

Separator layer 36 may be permeated with an electrolyte having suitableion transport properties, for example ethylene carbonate or diethylcarbonate containing lithium ion complexes. In lithium and lithium ionapplications of battery 10, the electrolyte is typically non-aqueous, inorder to avoid reacting with any lithium metal components of batterycore 28.

Carbon nanotube materials may also be used, for example extending fromthe anode base (layer 32 or 37), so that lithium ions are maintained byattachment to the (conducting) carbon nanotube material. This contrastswith other designs, were lithium may be eaten away or otherwise lostfrom anode layer 32 or anode collector (or pad 37), raising the risk ofa short or other battery fault. Where a sufficient level of lithium ismaintained, using carbon nanotubes or other lithium retention elementsin one or both of anode layer 32 and anode collector layer 37, battery10 remains effective over periods of extended use, including repeatedcharge and drain cycles.

In discharge operations of battery 10, for example oxidation may takeplace in anode layer 32, so that anode layer 32 functions as a negativeelectrode. Thus, anode collector 37 may have a relatively negativecharge, providing electron flow to the external circuit. Reductionreactions may take place in cathode layer 34, so that cathode layer 34functions as a positive electrode. Thus, cathode collector 39 may have arelatively positive charge, accepting electron flow from the externalcircuit. In secondary battery systems 10, recharging operations may besupported, where the current flow and oxidation reduction reactions arereversed. The charge flow in (or designations of) anode layer 32 andcathode layer 34 may also be reversed, depending on usage andnomenclature, and as described above.

FIG. 4 is an alternate cross-sectional view of battery 10, showing theinternal laminar structure of battery core 28 in a non-inverted orsingle-sided stack configuration. In this design, anode layers 32 andcathode layers 34 alternate across the height of battery 10, between topand bottom battery casings 12. An additional insulating spacer layer 40is provided between adjacent anode carrier layer 37 and cathode carrierlayer 39. Again, the number of individual layers is arbitrary, and maybe increased or decreased depending on layer thickness, batteryconfiguration, and battery form factor.

The design of FIG. 4 has a substantially uniform layering configuration,with separate anode and cathode carrier layers 37 and 39 for each anodelayer 32 and cathode layer 34, respectively. An additional spacer,insulator, or insulating substrate layer 40 may be included, adding tothe relative volume of passive material layers 28B, but any suchincrease may be relatively nominal because the planar structure ofbattery core 28 does not require additional spacing tolerance toaccommodate high curvature end regions, as characteristic of rolledbattery core designs.

For example, in some rolled battery core designs, a minimum tolerance ofabout 20 microns or more is required between adjacent anode and cathodepads or carrier layers 37 and 39, in order to reduce the risk ofshorting in end-roll regions with high curvature. In other designs, therequired tolerance may be even greater, for example more than about 50microns, or even more than about 100 microns. In the substantiallyplanar configuration of battery core 28, however, there is little orsubstantially no curvature, and the minimum required thickness forinter-pad (insulation) layer 40 may be less than 20 microns, for exampleabout 10 microns or less, or about 8 microns or less.

FIG. 5 is a schematic diagram of method 50 for producing a laminarbattery core, for example laminar core 28 of battery assembly 10, asshown in FIGS. 1-4, and as described above. Method 50 includes one ormore steps selected from deposition (step 51), baking or annealing (step52), encapsulation (step 53), adding electrolyte and separator (step54), and completing the battery core or core stack element (step 55).

Deposition (step 51) may include depositing an anode slurry on an anodecollector or anode collector substrate, depositing a cathode slurry on acathode collector or cathode collector substrate, or both. The lateraldimensions of the deposited anode and cathode materials may be definedby positioning a screen or electrode mask with respect to the collectorsubstrates. The thickness or depth d of the anode and cathode layers maybe controlled by translating a silkscreen blade or other mechanicalelement across the mask or screen, as illustrated in step 51 of FIG. 5.

Baking/Annealing (step 52) may include heating the mask or masks withthe anode or cathode slurry materials in order to anneal or harden thematerials into a suitable form for use in a battery or battery corestack. Depending on embodiment, a nickel iron alloy such as INVAR orKOVAR may be utilized for the mask, or another material with a low orparticularly selected (matched) coefficient of thermal expansion (CTE),in order to maintain particular dimensions with respect to the anode andcathode material during the heating in step 52, and in any subsequentcooling process.

Encapsulation (step 53) may include removing the electrode mask andpositioning a secondary or encapsulation mask with respect to the anodeor cathode layers, and/or the corresponding collector substrates. Anencapsulant such as a thermoplastic or other polymer may then bedeposited about the anode and cathode layers based on the encapsulationmask geometry. The encapsulant may be cured by heating, ultravioletradiation, or chemical means. Alternatively, a self-curing encapsulantcompound may be utilized, for example an epoxy resin.

Electrolyte and separator components are added in step 54. For example,a permeable separator material may be applied to either or both of theanode or cathode layer, and the separator material may be saturated orpermeated with an electrolyte material. Additional encapsulant may alsobe applied along the separator layer.

In step 55, the anode and cathode layers are joined in an adjacentrelationship to form a laminated battery core element, with theelectrolyte-permeated separator positioned between adjacent anode andcathode layers, and the electrode and cathode collector layerspositioned on the electrode and cathode layers, respectively. Ingeneral, the collector layer may be positioned opposite the separatorlayer, as defined across the respective anode and cathode layers.

The individual core stack elements can be assembled in a variety ofdifferent configurations to form the battery core, for example asdescribed above with respect to FIGS. 3 and 4, above, and in FIGS.6A-6C, 7A-7C, and 8-10, below. Suitable techniques include, but are notlimited to, optical positioning, robotic positioning, optical deviceassembly techniques, and other suitable positioning techniques forassembly battery core or core stack 28.

The laminated core structure of battery 10 and method 50 provides a moreuniform battery core structure than a rolled battery design, with moreprecise control of critical dimensions including individual layerthicknesses. By reducing thickness requirements in the separator andother passive or inactive components, moreover, energy density isincreased, for improved performance within a given form factor or volumeenvelope.

Battery lamination method 50 also provides a greater selection range forindividual (active and passive) layer thicknesses, including thickeractive anode and cathode layers. In thicker and “superthick”embodiments, the battery core is more “z efficient,” with a higherdensity of active materials along the vertical (thickness) dimension ofthe battery core, perpendicular to the individual layers, and betweenthe major surfaces in a flat profile battery design.

Limitations on layer thickness are primarily based on manufacturingconsiderations, and mask-to-mask (or roll to roll) variations. There mayalso be a relationship between anode and cathode thickness and iontransport capability. Where thicker anode and cathode layers may beachieved by silk screening or other lamination methods 50, edgedeterioration effects may be mitigated using a conformal coating orencapsulant to seal the edges of the battery core, as described above.

FIG. 6A is a cross-sectional illustration of cathode layer 34 for alaminar battery core, for example battery core 28 of FIGS. 1-4. Arelatively thick layer of cathode material 34 is deposited on cathodesubstrate 39, for example lithium cobalt oxide material using a maskingor screening process, as described above, or via another process such assputtering or chemical vapor deposition (CVD). Encapsulant or conformalcoating material 16 may be applied to seal the sides or edges of cathodelayer 12.

A separator/electrolyte or ion transport layer 36 can be deposited ontop of cathode layer 34, opposite cathode substrate layer 39. Dependingupon application, a lithium phosphate, lithium phosphorous, or lithiumphosphorous oxynitride (LiPON or LiPO_(x)N_(y)) material may be utilizedfor separator layer 36, for example to replace the traditional lithiumion transfer electrolyte and separator material with a glassy or thinfilm solid electrolyte separator layer 36. In additional configurations,a lithium polymer battery configuration may be utilized, using alithium-salt type electrolyte in a substantially solid polymer compositefor separator layer 36.

FIG. 6B is a cross-sectional illustration of anode and cathode layers 32and 34 for laminar battery core 28. Anode layer 32 is formed onseparator layer 36, opposite cathode layer 34, for example by physicalvapor deposition (PVD) or powder deposition of a lithium material.Alternatively, anode layer 32 may be formed of different material suchas graphite, and anode layer 32 may be applied via a screening ormasking method, for example as described above with respect to method 50of FIG. 5.

FIG. 6C is a cross-sectional illustration of battery core element 60,including anode and cathode layers 32 and 34 separated by separatorlayer 36. Battery core element 60 also includes anode and cathodecollector layers 37 and 39, as positioned adjacent to and in electricalcontact with anode and cathode layers 32 and 34, respectively, oppositeseparator layer 36. Encapsulant or conformal coating 16 and flexiblesealant 62 are provided to seal the sides of battery core element 60,including cathode layer 32, separator layer 36, and anode layer 32.

Flexible sealant 60 may be formed of an insulating material such as aroom temperature vulcanizing (RTV) silicone or other silicone orpolymer-based material, or an encapsulant or conformal coating. Similar,encapsulant 16 may be formed of a flexible sealant, such as RTV siliconeor other silicone or polymer based material.

FIG. 7A is a schematic illustration of core stack element 60,illustrating different external connector configurations. As shown inFIG. 7A, anode collector 37 may extend to external connection point 37Aon the same side of stack element 60 as cathode collection point 39A, asdefined for cathode collector 39. Alternatively, anode collector 37 mayextend to external connection point 37B, on the opposite side of stackelement 60 with respect to cathode collection point 39A.

FIG. 7B is a schematic illustration of battery core 28, in a single-sidestack configuration. In this configuration, individual stack elements 60are stacked together in the same orientation, with anode collectors 37extending to anode connection points 37B along one side of battery core(or stack) 28, and cathode collectors 39 extending to cathode connectionpoints 39A on the opposite side of battery core (or stack) 28. Thisallows all the cathode lines to be coupled to a single cathode output,and all the anode lines to be coupled to a single anode output, thusmaking the battery have a single cathode and a single anode.

FIG. 7C is a schematic illustration of battery core 28 in thesingle-stack configuration, illustrating representative layerthicknesses (in microns). In this particular configuration, cathodelayer 34 has a thickness of about 10 microns, or about 25% of the totalstack thickness of about 40 microns, including two conformal coating orencapsulation layers 16 of about 3 microns each, anode and cathodecollector layers (or substrates) 37 and 39 of about 8 microns each,separator layer 36 of about 2 microns, and anode layer 32 of about 6microns.

This results in a net or average cathode stacking efficiency of about25% or more for battery core (or stack) 28, as defined by the fractionof the battery thickness occupied by cathode layers 34. This result issubstantially higher than in other battery designs, providing batterycore 28 (and battery 10) with greater energy storage density andcapacity. In thicker embodiments, cathode layer 34 may have a thicknessof up to 25 microns or more, or more than 40% of the total stackthickness, for example about 45% of the total stack thickness.

FIG. 8 is a schematic illustration of battery core (or core stack) 28 ina double-sided stack configuration. In this example, one core or stackelement 60 is inverted with respect to the other, as described abovewith respect to FIG. 3, using a single cathode collector 39 between twoadjacent cathode layers 34. In this configuration, the vertical cathodeefficiency may be about 30% or more (about 30.3%), based on two cathodelayers 34 with a total thickness of about 20 microns, in a stack withtwo anode layers 34 at about 6 microns each, two separator layers 36 atabout 2 microns each, two conformal coating layers 16 at about 3 micronseach, two anode collectors 37 at about 8 microns each, and only onecathode collector 39 at about 8 microns (about 66 microns total). Forthicker cathode designs of up to 25 microns or more, the cathodestacking efficiency may be higher, for example about 50% or more.

FIG. 9 is a schematic illustration of battery core or stack 28 in asingle-sided, double stack configuration. This is similar to the exampleof FIG. 8, but with stack elements 60 inverted so that a single anodecollector 37 is positioned between two adjacent anode layers 32. Therelative stacking thicknesses are approximately the same, as describedabove with respect to FIG. 8, resulting in a vertical cathode stackingefficiency of about 30% (or 30.3%)

FIG. 10 is a schematic illustration of battery core or stack 28, in amulti-stack configuration. In this particular example, battery stack 28includes two separate instances of the single-sided, double stackconfiguration of FIG. 9. Alternatively, battery stack 28 may compriseone, two, three, four or more core stack elements, using any of thestacking configurations shown in FIG. 3, 4, 7A-7C, 8, or 9.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the invention.However, it will be apparent to one skilled in the art that the specificdetails are not required in order to practice the invention. In otherinstances, well known circuits and devices are shown in block diagramform in order to avoid unnecessary distraction from the underlyinginvention. Thus, the foregoing descriptions of specific embodiments ofthe present invention are presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, obviously many modificationsand variations are possible in view of the above teachings. Theembodiments were chosen and described in order to best explain theprinciples of the invention and its practical applications, to therebyenable others skilled in the art to best utilize the invention andvarious embodiments with various modifications as are suited to theparticular use contemplated. It is intended that the scope of theinvention be defined by the following claims and their equivalents.

We claim:
 1. A battery assembly comprising: a battery casing; and abattery core disposed within the battery casing, the battery corecomprising at least first and second substantially planar core stackelements, each of the core stack elements comprising: an anode activematerial layer; a cathode active material layer; a separator layertherebetween; and an anode collector layer adjacent to the anode activematerial layer; wherein: the battery assembly has a cathode activematerial layer stacking efficiency of at least about 30% of a thicknessof the battery core; and the thickness of the battery core is less thanapproximately 100 microns.
 2. The battery assembly of claim 1, whereineach of the core stack elements extends substantially across atransverse area of the battery core.
 3. The battery assembly of claim 2,further comprising a cathode collector layer adjacent and in electricalcontact with each of the cathode active material layers, opposite therespective separator layer.
 4. The battery assembly of claim 3, furthercomprising carbon nanotubes, to which additional lithium ions areattached, extending from the anode active material layer.
 5. The batteryassembly of claim 1, wherein the first and second core stack elementshave inverted orientations within the battery core.
 6. The batteryassembly of claim 5, wherein the cathode active material layers of thefirst and second core stack elements are adjacent, and furthercomprising a shared cathode collector layer between the adjacent cathodeactive material layers.
 7. The battery assembly of claim 5, wherein theanode active material layers of the first and second core stack elementsare adjacent and the anode current collector layers of the first andsecond core stack elements are shared.
 8. The battery assembly of claim5, wherein the battery assembly has the cathode active material layerstacking efficiency of at least about 40%.
 9. The battery assembly ofclaim 8, wherein the cathode active material layer is thicker than aseparation between the cathode active material layer and the anodeactive material layer.
 10. The battery assembly of claim 1, wherein thefirst and second core stack elements have a substantially sameorientation within the battery core.
 11. The battery assembly of claim10, wherein the cathode active material layer of the first core stackelement is adjacent the anode active material layer of the second corestack element.
 12. The battery assembly of claim 11, further comprisinga spacer layer between the cathode active material layer of the firstcore stack element and the anode active material layer of the secondcore stack element.
 13. The battery assembly of claim 10, wherein thebattery assembly has the cathode active material layer stackingefficiency of at least about 45%.
 14. The battery assembly of claim 13,wherein the cathode active material layer is thicker than the separatorlayer.
 15. The battery assembly of claim 14, wherein the cathode activematerial layer has a thickness of greater than about 20 microns.
 16. Thebattery assembly of claim 1, further comprising a third core stackelement, wherein the first, second and third core stack elements havealternating stacking orientations in the battery core.
 17. The batteryassembly of claim 1, further comprising third and fourth core stackelements, wherein the first and fourth core stack elements havesubstantially inverted stacking orientations in the battery core, withthe second and third core stack elements therebetween.
 18. The batteryassembly of claim 17, wherein the second and third core stack elementshave substantially inverted stacking orientations between the first andfourth core stack elements.
 19. A battery assembly comprising: a batterycore having a thickness of less than approximately 100 microns; aplurality of layers extending across a transverse area of the batterycore, the plurality of layers comprising; at least one cathode activematerial layer; at least one anode active material layer; at least oneseparator layer therebetween; and an anode collector layer; wherein: theplurality of layers are substantially planar across the transverse areaof the battery core, such that the battery core has a substantiallylaminar and planar and geometry; a separation between the at least onecathode active material layer and the at least one anode active materiallayer is thicker than the at least one cathode active material layer;and a cathode active material layer stacking efficiency of the batterysystem is at least about 30%.
 20. The battery assembly of claim 19,further comprising a cathode collector layer adjacent to and inelectrical contact with the at least one cathode active material layer.21. The battery assembly of claim 20, wherein the at least one cathodeactive material layer comprises a first cathode active material layer,and further comprising a second cathode active material layer adjacentto and in electrical contact with the cathode collector layer, oppositethe first cathode active material layer.
 22. The battery assembly ofclaim 19, further comprising an wherein the anode collector layer isadjacent to and in electrical contact with the at least one anode activematerial layer.
 23. The battery assembly of claim 20, wherein the atleast one anode active material layer comprises a first anode activematerial layer, and further comprising a second anode active materiallayer adjacent to and in electrical contact with the cathode collectorlayer, opposite the first anode active material layer.
 24. The batteryassembly of claim 19, further comprising a spacer layer adjacent the atleast one anode active material layer.
 25. The battery assembly of claim24, wherein the at least one cathode active material layer comprises afirst cathode active material layer and further comprising a secondcathode active material layer adjacent the spacer layer, opposite the atleast one anode active material layer.
 26. The battery assembly of claim19, wherein the cathode active material layer stacking efficiency of thebattery system is at least about 30% over substantially the entiretransverse area of the battery core, an average of the cathode activematerial layer stacking efficiency defined by a fraction of a thicknessof the battery core.
 27. The battery assembly of claim 26, wherein thecathode active material layer stacking efficiency is at least about 35%over substantially the entire transverse area of the battery core. 28.The battery assembly of claim 27, wherein the cathode active materiallayer stacking efficiency is at least about 40% over substantially theentire transverse area of the battery core.
 29. The battery assembly ofclaim 19, further comprising a battery case disposed about the batterycore.
 30. A method of forming a core stack for a battery core, themethod comprising: forming an anode active material layer on an anodecarrier substrate; forming a cathode active material layer on a cathodecarrier substrate; forming a separator layer on at least one of theanode active material layer and the cathode active material layer;forming an anode collector layer adjacent to the anode active materiallayer; and assembling the anode active material layer and cathode activematerial layer into a battery stack element, wherein the anode activematerial layer and the cathode active material layer are adjacent acrossthe separator layer in the battery stack element, the cathode activematerial layer stacking efficiency of the battery stack element is atleast 30% of a thickness of the battery stack element, and the thicknessof the battery stack element is less than approximately 100 microns. 31.The method of claim 30, wherein forming at least one of the anode activematerial layer and the cathode active material layer comprisingdepositing a slurry on the respective substrate.
 32. The method of claim31, wherein depositing the slurry is defined by a mask positioned on therespective substrate.
 33. The method of claim 30, wherein forming atleast one of the anode active material layer and the cathode activematerial layer comprises vapor deposition of a metal onto the respectivesubstrate.
 34. The method of claim 30, wherein forming at least one ofthe anode active material layer and the cathode active material layercomprises a screening process.
 35. The method of claim 30, furthercomprising annealing the anode active material and cathode activematerial layers.
 36. The method of claim 35, wherein at least one of theanode active material and cathode active material layers is formedwithin a mask material, the mask material comprising a nickel ironalloy.
 37. The method of claim 30, wherein the nickel iron alloy isselected from a group comprising INVAR and KOVAR.
 38. The method ofclaim 30, further comprising encapsulating at least one of the anodeactive material layer and the cathode active material layer.
 39. Themethod of claim 38, wherein encapsulating at least one of the anodeactive material layer and the cathode active material layer comprisingpositioning an encapsulating mask adjacent the respective anode activematerial layer or cathode active material layer.
 40. The method of claim30, wherein forming the separator layer comprises depositing lithium andphosphor onto one or both of the anode active material and cathodeactive material layers.
 41. The method of claim 40, wherein forming theseparator layer comprises depositing a lithium polymer separator layeronto one or both of the anode active material and cathode activematerial layers.
 42. The method of claim 40, further comprisingassembling a plurality of the battery stack elements into a batterycore.
 43. The method of claim 42, wherein at least two adjacent batterystack elements have inverted stacking orientations in the battery core.44. The method of claim 42, wherein at least two adjacent battery stackelements have a same stacking orientation in the battery core.
 45. Themethod of claim 42, further comprising encapsulating the battery core.46. The method of claim 42, further comprising forming a battery caseabout the battery core.
 47. The method of claim 42, further comprisingcharging the battery core.
 48. The method of claim 47, furthercomprising discharging the battery core.
 49. The method of claim 30,wherein forming at least one of the anode active material layer and thecathode active material layer comprises depositing a slurry into a wellformed on the respective substrate.
 50. The method of claim 49, whereinforming at least one of the anode active material layer and the cathodeactive material layer comprises depositing the slurry by ejectionmolding.